[ENBD] Problems compiling 2.4.26a on RH6.2 kernel 2.2.19

[Peter T. Breuer]

"A month of sundays ago Nelson Vieira wrote:"
> Well that seemed to have done the trick. It now successfully compiles nbd.o

What did do the trick, exactly?

> with the following warnings:
> 
> gcc -O2 -Wall -D_LARGEFILE64_SOURCE -D__KERNEL__ -DMODULE -DDEBUG=0 -I/home/
> neno/nbd-2.4.26a/linux/include -I/usr/src/linux/include  -c -o nbd.o
> /home/neno/nbd-2.4.26a/linux/drivers/block/nbd.c
> /home/neno/nbd-2.4.26a/linux/drivers/block/nbd.c:227: warning: `module_init'

Well, I did say to put #ifndef's around the definitions!

> redefined

> /home/neno/nbd-2.4.26a/linux/drivers/block/nbd.c:259: warning: static
> declaration for `mark_buffer_protected' follows non-static

This is the interesting one. Can you find the other definition? The one
near line 259 in nbd.c is

 static inline void mark_buffer_protected(struct buffer_head * bh) {
         if (!atomic_set_buffer_protected(bh))
             refile_buffer(bh);
 }

and it is protected by a

 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,3,30)

which I presume is now invalidated by marcello's backport of the
function to 2.2.19.  I would be very grateful if you could check,
perhaps linux/fs.h, and show me the kernel definition, if you find it
there (or elsewhere).

> /home/neno/nbd-2.4.26a/linux/drivers/block/nbd.c: In function
> `cleanup_module':
> /home/neno/nbd-2.4.26a/linux/drivers/block/nbd.c:4912: warning: control
> reaches end of non-void function

I also don't like that! The function nbd_cleanup is declared void! What
have you done exactly?


  void __exit
  ^^^^^
  nbd_cleanup (void)
  {


> make[1]: Leaving directory `/tmp'
> 
> I'm not, but any means, a Linux system programmer, but this looks OK to me.

Not to me! (ps - a systems programmer is not a kernel programmer! It's
usually a very different world).

So what changes did you make? Did you define __init and __exit to
nothing, or to the modifier I suggested? If the latter, I think you
must have got something slightly wrong, because the cleanup function is
declared void ... aha, I see.


We have a slight difficulty in that module_exit() wanted a return
value from the function that is its argument.  Try this instead:

     #define module_exit(x) int cleanup_module(void) { x(); return 0; }


Peter